Hydration alert

Abstract

One aspect of the invention is an apparatus including an alarm for alerting an operator to recharge a humidifier, wherein such alarm is generated other than through the use of a humidity sensor. In one embodiment the total work performed during heating and hydrating an insufflation gas is measured and an alarm generated when the total work performed exceeds a particular threshold. In another embodiment, a flow meter is used to measure the total flow of insufflation gas so that when the total flow of insufflation gas reaches a predetermined level an alarm is activated.

1. An apparatus for alerting an operator to refill a heater hydrator which receives gas from a laparoscopic insufflator, the heater hydrator comprising a heater, the apparatus comprising:
 a sensor that provides a signal that may be used to determine the work performed by the heater in heating and hydrating a gas using the heater hydrator; 
 a control circuitry connected to the sensor, including an internal power sensor that makes a series of measurements over a time period in order to calculate the total work performed by the heater and said control circuitry operable to determine when the total work performed by the heater exceeds a threshold level; 
 an alarm, wherein the control circuitry activates the alarm in response to a determination that the total work performed exceeds the threshold level. 
 
     
     
       2. The apparatus of  claim 1  wherein the heater hydrator includes a charging port. 
     
     
       3. The apparatus of  claim 1  wherein the alarm comprises an audible alarm. 
     
     
       4. The apparatus of  claim 1  wherein the control circuitry comprises a microcontroller. 
     
     
       5. An alert system for use during a medical procedure comprising:
 a temperature sensor for providing a temperature signal; and 
 a circuitry responsive to a change in a pattern of the temperature signal for determining when a heater hydrator used with a laparoscopic insufflator should be recharged with a humidifying liquid in response to the change in the pattern of the temperature signal from the temperature sensor. 
 
     
     
       6. The alert system of  claim 5 , further comprising:
 an alarm responsive to an alert signal from the circuitry wherein the alarm is activated when a recharge determination is made by the circuitry. 
 
     
     
       7. The alert system of  claim 5 , further comprising:
 a further sensor for providing a further signal that may be used to estimate at least one of instantaneous power consumption of a heater, work done by a heater, or gas flow; and 
 wherein the circuitry makes a recharge determination in response to the signal from the temperature sensor and the further signal from the further sensor. 
 
     
     
       8. The alert system of  claim 5  wherein the alert system includes a flow meter. 
     
     
       9. The alert system of  claim 5  wherein an alarm is activated when the change in the pattern of the temperature signal from the temperature sensor changes during a time period and both exceeds a high threshold and drops below a low threshold during that time period. 
     
     
       10. A method to determine when to recharge a heater hydrator comprising:
 supplying an insufflation gas to a heater hydrator from a laparoscopic insufflator comprising a heater; 
 determining a change in a temperature pattern of the insufflation gas from a temperature signal having a constant output to an erratic output; and 
 activating an alarm in response to the determination of the change in the temperature pattern of the insufflation gas. 
 
     
     
       11. The method of  claim 10  further comprising:
 recharging the heater hydrator before all hydration fluid contained therein has been consumed. 
 
     
     
       12. The method of  claim 11  wherein the step of determining the change in the temperature pattern includes determining the work performed by the heater. 
     
     
       13. The method of  claim 12  wherein the alarm is activated by using electrical power measurements to determine the work performed by the heater during a particular time period. 
     
     
       14. The method of  claim 10  wherein the step of activating an alarm comprises activating a visual alarm. 
     
     
       15. The method of  claim 10  wherein the step of activating an alarm comprises activating an audible alarm. 
     
     
       16. The method of  claim 10  further comprising monitoring the temperature pattern proximate the exit of the heater hydrator and disabling the heater when the temperature changes in a way over time such that it both exceeds a high temperature threshold and drops below a low temperature threshold during a time period. 
     
     
       17. The method of  claim 10 , further comprising disabling the heater after instantaneous electrical power supplied to the heater falls below a particular threshold when power is being supplied to the heater and when gas is flowing through the heater hydrator. 
     
     
       18. The method of  claim 10  including the step of monitoring a temperature of the insufflation gas after it has been humidified by the heater hydrator. 
     
     
       19. The method of  claim 10 , further comprising recharging the heater hydrator in response to the alarm. 
     
     
       20. The method to determine when to recharge a heater hydrator comprising:
 making a series of power measurements during a time period; 
 calculating the work performed by the heater hydrator using the power measurements and the time period; 
 determining both work performed by the heater and the total volume of insufflation gas supplied to the heater hydrator; and 
 activating the alarm in response to both determinations.